Question

Distance to Finish Line
(meters)
Jasen
-8t+200
Mary
-7.5t+ 200

Jason and Mary are running an a 200 meter track.
The expressions in the table above show the
distance to the finish line t seconds after they
started the race. How many meters will Mary have
Ieft to finish the race when Jason is on the finish
line?
​

Answer 1

Answer:

12.5 meters

Explanation:

Given

$J(t) = -8t + 200$ --- Jasen

$M(t) = -7.5t + 200$ --- Mary

Required

Determine the number of metres left for Mary when Jason finishes

When Jasen finishes the race;

$J(t) = 0$ -- Because Jasen is already at the stoppage

So, we need to calculate time spent by Jasen to get to the finished line.

$J(t) = -8t + 200$

Substitute 0 for J(t)

$0 = -8t + 200$

Collect like terms

$8t = 200$

Solve for t

$t = \frac{200}{8}$

$t = 25$

What this implies is that: we want to get Mary's distance at time; $t = 25$

Substitute 25 for t in $M(t) = -7.5t + 200$

$M(25) = -7.5 * 25 + 200$

$M(25) = -187.5 + 200$

$M(25) = 12.5$

Hence, Mary has 12.5 metres left